PIC16C662-10I/SP Microchip Technology, PIC16C662-10I/SP Datasheet - Page 53

• Manufacturer Part Number: PIC16C662-10I/SP
• Description: 8-Bit EPROM Microcontrollers with Analog Comparators
• Manufacturer: Microchip Technology

8.0
The Voltage Reference is a 16-tap resistor ladder
network that provides a selectable voltage reference.
The resistor ladder is segmented to provide two ranges
of V
conserve power when the reference module is not
being used.
FIGURE 8-1:
FIGURE 8-2:
VREN
1996 Microchip Technology Inc.
bit7
bit 7:
bit 6:
bit 5:
bit 4:
bit 3-0: VR3:VR0 : V
R/W-0
VREN
Note:
REF
VOLTAGE REFERENCE
MODULE
values and has a power-down function to
VREN: V
1 = V
0 = V
VROE: V
1 = V
0 = V
VRR: V
1 = Low Range
0 = High Range
Unimplemented: Read as '0'
When: VRR = 1
Then: V
When: VRR = 0
Then: V
R is defined in Table 12-3.
R/W-0
VROE
REF
REF
REF
REF
V
VOLTAGE REFERENCE BLOCK DIAGRAM
VRCON REGISTER (ADDRESS 9Fh)
REF
REF
REF
REF
REF
REF
circuit powered up
circuit powered down, no I
is output on RA2 pin
is disconnected from RA2 pin
Range selection
= (VR3:VR0/ 24) • V
= 1/4 • V
REF
R/W-0
Enable
Output Enable
VRR
value selection 0
This document was created with FrameMaker 4 0 4
8R
DD
U-0
—
+ (VR3:VR0/ 32) • V
R
R/W-0
VR3
DD
DD
VR3:VR0
R
Preliminary
drain
PIC16C64X & PIC16C66X
R/W-0
VR2
16 Stages
DD
16-1 Analog Mux
15
The VRCON register, shown in Figure 8-1, controls the
operation of the Voltage Reference Module. The block
diagram is given in Figure 8-2.
R/W-0
VR1
R
bit0
R/W-0
VR0
R
R =Readable bit
W =Writable bit
U =Unimplemented bit, read
as ‘0’
- n =Value at POR reset
8R
VR3
VR2
VR1
VR0
(From VRCON<3:0>)
DS30559A-page 53
VRR